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1, Delay queue and dead letter queue Dead letter queue: elements are not consumed in time after they are generated and are always stored in the queue. Delay queue: the delay queue has a sequence within the queue. Its most important feature is the delay time. It wants to be taken out and processed after or before the specified time. It is simi ...

concept When we develop stand-alone applications and synchronize level concurrency, we often use synchronized or Lock to solve the problem of code synchronization between multiple threads. At this time, multiple threads run under the same JVM without any problem. However, when our application works in a distributed cluster, it belongs to a w ...

Message loss scenario There are three main scenarios for MQ message loss: 1. The rabbitmq server does not receive the message sent by the message producer; Cause message loss 2.rabbitmq does not persist the message after receiving it, resulting in message loss 3. After receiving the message, the consumer did not have time to deal with it, and ...

1, Introduction shardingsphere is a product of Apache, mainly including Sharding JDBC and Sharding Proxy. The former can be regarded as an enhanced version of JDBC, and the latter is an independent proxy system without coupling in the code. In this regard, it is very similar to Mycat 2, What did ShardingJDBC do for me? When using Shardi ...

Principle of Redis implementing distributed lock We talked about the application of Redis in the actual business scenario. Now let's learn about the application of Redisson functional scenario, that is, the implementation scenario of distributed locks that we often use. Introduce redisson dependency <dependency> <groupId>org. ...

I. overview           In RabbitMQ, by default, the message will not expire when the message expiration parameter is not set. Even if the message is not consumed, the message will always be stored in the queue. Second queue message lifetime TTL         TTL (time to live), the time that the message ...

nacos instructions 1. Installation / deployment Download the corresponding installation package from the official website: https://nacos.io/zh-cn/index.html For example, nacos-server-2.0.2.tar.gz Upload server, unzip: eyecool@eyecool-OptiPlex-7060:~/nacos/nacos$ ls -l Total consumption 44 drwxrwxr-x 4 eyecool eyecool 4096 7 June 14:29 bin ...

Distributed data storage solution for 100 million users 1 1. Introduction MySQL Cluster is a high-performance, scalable and clustered database product. Its original intention of R & D and design is to meet the most severe application requirements in many industries. In these applications, the reliability of database operation is often ...

Computing services (nova) overview Use OpenStack Compute to host and manage cloud computing systems. OpenStack computing is a major part of infrastructure as a service (IaaS) systems. The main module is implemented in Python. OpenStack Compute interacts with OpenStack Identity for authentication, with OpenStack Placement for inventory tracking ...

In the previous article, we introduced the implementation of RPC basic services. Now we will go on to how to make an RPC service into a standard product and what needs to be implemented. It is not enough for our service consumers to only realize remote invocation, which is still a long way from commercialization. The core functions of Consume ...